ELECTRODEPOSITION COATING METHOD

• Main Authors: SEO HIROSHI, MURAKAMI RYOICHI
• Format: Patent
• Language: English
• Published: 27.05.1997
• Edition: 6
• Subjects: APPARATUS THEREFOR; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; METALLURGY; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS; SPRAYING OR ATOMISING IN GENERAL; TRANSPORTING

PROBLEM TO BE SOLVED: To provide an electrodeposition coating method capable of improving the uniformity of coating in electrodeposition coating, decreasing the amt. of a coating material to be carried out, suppressing a gas pin in cation electrodeposition and simultaneously facilitating the management of an electrodeposition coating system including the prevention of the clogging of an ultrafilter device. SOLUTION: This two-stage type electrodeposition coating method comprises executing electrodeposition with the first vessel 1 of an electrodeposition bath having an electrodeposition coating material concn. of 10 to 35wt.% non-volatile content, then executing electrodeposition with the second vessel 2 of the electrodeposition bath having the non-volatile content lower by >=1wt.% than in the first vessel. Further, the first vessel 1 is replenished with the replenishing coating material. At least a part of the washing water including the carried out coating material generated by the washing of the material to be coated is returned to the second vessel 2. At least a part of the electrodeposition bath of the second vessel is subjected to ultrafiltration and at least a part of the concd. liquid is returned to the second vessel. The impressed voltage of the first vessel is set lower by 10 to 200 volts than the impressed voltage in the second vessel.